This proposal requests funding for a half-day symposium entitled "Tobacco Carcinogenesis" to be held at the 230th American Chemical Society (ACS) National Meeting, between August 28th and September 1st, 2005, in Washington, D.C., and sponsored by the Division of Chemical Toxicology of the ACS. Tobacco carcinogenesis is the study of the mechanisms by which tobacco products cause cancer. There have been no symposia on this topic at national or international meetings in the past five years. In a poll taken earlier this year, members of the Division of Chemical Toxicology chose tobacco carcinogenesis as their highest priority for a symposium at the 2005 meeting. The topic is timely in view of recent reports by the International Agency for Research on Cancer and the U.S. Surgeon General highlighting the immense current cancer death toll from tobacco use. The symposium will feature seven 30 minute presentations and a panel discussion. The co-chairs will be Dr. Stephen S. Hecht and Dr. Mirjana Djordjevic. Dr. Hecht will present an overview of tobacco carcinogenesis. This will be followed by a presentation by Dr. Jack Henningfield on nicotine addiction and why people smoke. Dr. David Ashley will review carcinogens in tobacco products. Dr. Trevor Penning will discuss recent work on mechanisms of bioactivation of polycyclic aromatic hydrocarbons. Dr. Sharon Murphy will discuss cytochrome P450-mediated metabolism of tobacco-specific nitrosamines and nicotine. Dr. Peter Shields will review biomarkers of carcinogen uptake and activation which are currently being applied in studies of tobacco users. Dr. Mimi Yu will present recent data on the molecular epidemiology of tobacco-related cancer. The panel discussion will feature scientists with differing backgrounds and affiliations. It will be moderated by Dr. Hecht. Participants are Dr. Djordjevic (National Cancer Institute), Dr. Steven Tannenbaum (MIT), Dr. Jack Henningfield (Johns Hopkins and Pinney Associates), Drs. Jeffrey Seeman and Anthony Tricker (Philip Morris), and Dr. John Lauterbach (an independent consultant, formerly with Brown and Williamson).